Change graphs to only show top 7

@@ -214,7 +214,7 @@ def property(request, property_id):                "count": event["count"],            }        )    context["total_events_by_screen_size"] = total_events_by_screen_size    context["total_events_by_screen_size"] = total_events_by_screen_size[:7]    #    # Total events by device graph

@@ -232,7 +232,7 @@ def property(request, property_id):            total_events_by_device.append(                {"label": event["data__device"], "count": event["count"]}            )    context["total_events_by_device"] = total_events_by_device    context["total_events_by_device"] = total_events_by_device[:7]    #    # Total events by browser graph

@@ -250,7 +250,7 @@ def property(request, property_id):            total_events_by_browser.append(                {"label": event["data__browser"], "count": event["count"]}            )    context["total_events_by_browser"] = total_events_by_browser    context["total_events_by_browser"] = total_events_by_browser[:7]    #    # Total events by platform graph

@@ -268,7 +268,7 @@ def property(request, property_id):            total_events_by_platform.append(                {"label": event["data__platform"], "count": event["count"]}            )    context["total_events_by_platform"] = total_events_by_platform    context["total_events_by_platform"] = total_events_by_platform[:7]    #    # Total events by page url list